Various compositions are known to be useful as treating agents to provide water repellency and optionally stain release to textile substrates. Many such treating agents are fluorinated polymers and copolymers, or non-fluorinated polymers and copolymers. Non-fluorinated compounds are predominately polyacrylate-based or urethane-based copolymers.
Fluorinated copolymers provide good repellency to water and oil. Various attempts have been made to produce a non-fluorinated water or low-fluorine content repellent. Non-fluorinated copolymers are known to provide water repellency and optionally stain release to textiles, but are less effective than the fluorinated counterparts.
Typically relatively high levels of fluorinated monomers are required for adequate performance. For instance, U.S. Pat. No. 6,479,605 discloses formulations that have about 40 to about 75 weight % of fluorinated monomer in useful formulations. Furthermore, to achieve effective repellency the monomers typically used in commercial formulations have long perfluorinated alkyl groups, usually mixtures, with a large fraction of the perfluorinated alkyl groups greater than six carbon atoms. It is desired to have treating agents for fibrous substrates containing less fluorine while maintaining repellency performance. Lee et al, in U.S. Pat. No. 6,790,898, discloses an emulsion particle with a core-shell structure wherein the shell contained many perfluorinated groups and the core contained few or no perfluorinated groups. In this core-shell structure, the hydrophobic shell was designed to provide high levels of hydrophobic functionality at the air-material interface. However, the compositions were designed to provide polymer films, and not surface treatment agents for fibrous products.